package com.test.mall.product.service.impl;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.TypeReference;
import com.test.mall.product.service.CategoryBrandRelationService;
import com.test.mall.product.vo.Catelog2Vo;
import org.apache.commons.lang.StringUtils;
import org.redisson.Redisson;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.cache.annotation.CachePut;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.cache.annotation.Caching;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;

import java.util.*;
import java.util.concurrent.TimeUnit;
import java.util.stream.Collectors;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.test.common.utils.PageUtils;
import com.test.common.utils.Query;

import com.test.mall.product.dao.CategoryDao;
import com.test.mall.product.entity.CategoryEntity;
import com.test.mall.product.service.CategoryService;
import org.springframework.transaction.annotation.Transactional;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Autowired
    private RedissonClient redisson;

    @Autowired
    private StringRedisTemplate redisTemplate;

    @Autowired
    CategoryBrandRelationService categoryBrandRelationService;

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    @Override
    public List<CategoryEntity> listWithTree() {
        //1、查出所有分类
        List<CategoryEntity> entities= baseMapper.selectList(null);
        //2、组装成树状分类
        List<CategoryEntity> level1Menus =entities.stream().filter(categoryEntity->
            categoryEntity.getParentCid() == 0
        ).map(menu->{
            menu.setChildren(getChildrens(menu,entities));
            return menu;
        }).sorted((menu1,menu2)->{
            return (menu1.getSort()==null?0:menu1.getSort()) - (menu2.getSort()==null?0:menu2.getSort());
        }).collect(Collectors.toList());


        return level1Menus;
    }

    @Override
    public void removeMenuByIds(List<Long> asList) {
        //TODO 1、检查当前删除的菜单，是否被别的地方引用

        baseMapper.deleteBatchIds(asList);
    }

    @Override
    public Long[] findCatelogPath(Long catelogId) {
        List<Long> paths = new ArrayList<>();
        List<Long> parentPath = findParentPath(catelogId,paths);

        Collections.reverse(parentPath);

        return parentPath.toArray(new Long[parentPath.size()]);
    }


    //级联更新所有数据
//    @Caching(evict = {
//            @CacheEvict(value = "category" , key = "'getLevel1Categorys'") ,
//            @CacheEvict(value = "category" , key = "'getCatalogJson'")
//    })//失效模式 同时进行多种操作
//    @CachePut //双写模式
    @CacheEvict(value = "category",allEntries = true)//删除某个区的数据 失效模式
    @Override
    @Transactional
    public void updateCascade(CategoryEntity category) {
        this.updateById(category);
        categoryBrandRelationService.updateCategory(category.getCatId(),category.getName());
    }


    // 每一个需要缓存的数据我们都来指定要放到那个名字的缓存
    //默认行为
    //  1、如果缓存中有，方法不调用
    //  2、key自动生成；缓存的名字 category::SimpleKey []
    //  3、缓存的value的值，默认使用jdk序列化机制，序列化后的数据窜到redis
    //  4、默认ttl时间 -1
    //自定义
    // 1、指定为实际的缓存使用的key spel语法  key = "#root.method.name"
    // 2、指定缓存的存活时间   配置文件中修改ttl
    // 3、将数据保存为json格式：CacheAutoConfiguration -> RedisCacheConfiguration -> 自动配置了RedisCacheManager
    @Cacheable(value = {"category"},key = "#root.method.name",sync = true) //代表当前方法需要缓存，如果缓存中有，方法不调用，如果缓存没有，调用方法将方法的结果放到缓存
    @Override
    public List<CategoryEntity> getLevel1Categorys() {
        System.out.println("方法调用了");
        List<CategoryEntity> categoryEntities = baseMapper.selectList(new QueryWrapper<CategoryEntity>().eq("parent_cid", 0));
        return categoryEntities;
    }

    @Cacheable(value = "category",key = "#root.methodName")
    @Override
    public Map<String, List<Catelog2Vo>> getCatalogJson() {
        List<CategoryEntity> selectList = baseMapper.selectList(null);
        //查出所有一级分类
        List<CategoryEntity> level1Categorys = getParent_cid(selectList,0L);
        //封装数据
        Map<String, List<Catelog2Vo>> parent_cid = level1Categorys.stream().collect(Collectors.toMap(k -> k.getCatId().toString(), v -> {
            //拿到每一个的一级分类,查到二级分类
            List<CategoryEntity> categoryEntities = getParent_cid(selectList,v.getCatId());
            List<Catelog2Vo> catelog2Vos = null;
            if (categoryEntities != null) {
                catelog2Vos = categoryEntities.stream().map(l2 -> {
                    Catelog2Vo catelog2Vo = new Catelog2Vo(v.getCatId().toString(), null, l2.getCatId().toString(), l2.getName());
                    //找当前二级分类的三级分类封装成vo
                    List<CategoryEntity> level3Catalog = getParent_cid(selectList,l2.getCatId());

                    if (level3Catalog!=null){
                        List<Catelog2Vo.Catelog3Vo> collect = level3Catalog.stream().map(l3 -> {
                            //封装指定格式
                            Catelog2Vo.Catelog3Vo catelog3Vo = new Catelog2Vo.Catelog3Vo( l2.getCatId().toString(), l3.getName() ,l3.getCatId().toString());
                            return catelog3Vo;
                        }).collect(Collectors.toList());
                        catelog2Vo.setCatalog3List(collect);

                    }

                    return catelog2Vo;
                }).collect(Collectors.toList());
            }
            return catelog2Vos;
        }));
        return parent_cid;
    }

    public Map<String, List<Catelog2Vo>> getCatalogJson2(){
        //给缓存中放json字符串，拿出的json字符串，还能逆转为能用的对象类型【序列化与反序列化】
        /**
         * 1、空结果缓存：解决缓存穿透
         * 2、设置过期时间（加随机值）：解决缓存雪崩
         * 3、加锁：解决缓存击穿
         */
        //加入缓存，缓存的数据是json字符串
        //json跨平台，跨语言
        String catalogJSON = redisTemplate.opsForValue().get("catalogJSON");
        if (StringUtils.isEmpty(catalogJSON)){
            //缓存中没有，查询数据库
            Map<String, List<Catelog2Vo>> catalogJsonFromDb = getCatalogJsonFromDbWithRedisLock();
            return catalogJsonFromDb;
        }

        //转为指定的类型
        Map<String, List<Catelog2Vo>> result = JSON.parseObject(catalogJSON,new TypeReference<Map<String, List<Catelog2Vo>>>(){});

        return result;
    }

    /**
     * 缓存数据一致性问题
     * 1、双写模式
     * 2、失效模式
     * @return
     */
    public Map<String, List<Catelog2Vo>> getCatalogJsonFromDbWithRedissionLock() {
        //1、锁的名称。锁的粒度，越细越大
        //锁的粒度：具体缓存的是某个数据，11-号商品：product-11-lock
        RLock lock = redisson.getLock("CatalogJson-lock");
        lock.lock();

        Map<String, List<Catelog2Vo>> dataFromDb;
        try{
            dataFromDb = getDataFromDb();
        }finally {
            lock.unlock();
        }

            return dataFromDb;

    }

    public Map<String, List<Catelog2Vo>> getCatalogJsonFromDbWithRedisLock() {
        //1、占分布式锁。去redis占坑
        String uuid = UUID.randomUUID().toString();
        Boolean lock = redisTemplate.opsForValue().setIfAbsent("lock", uuid,300,TimeUnit.SECONDS);
        if (lock) {
            //加锁成功....执行业务
            //设置过期时间,必须和加锁同步
            //redisTemplate.expire("lock",30,TimeUnit.SECONDS);
            Map<String, List<Catelog2Vo>> dataFromDb;
            try{
                dataFromDb = getDataFromDb();
            }finally {
                //获取值+对比成功删除=原子操作  lua脚本解锁
                String script = "if redis.call('get',KEYS[1]) == ARGV[1] then return redis.call('del',KEYS[1]) else return 0 end";
                //删除锁
                Long lock1 = redisTemplate.execute(new DefaultRedisScript<Long>(script, Long.class),
                        Arrays.asList("lock"), uuid);
            }
            
//            String lockValue = redisTemplate.opsForValue().get("lock");
//            if (uuid.equals(lockValue)) {
//                //删除自己的锁
//                redisTemplate.delete("lock");//删除锁
//            }

            return dataFromDb;
        } else {
            //加锁失败....重试
            //休眠100ms重试
            try {
                Thread.sleep(200);
            } catch (InterruptedException e) {
            }
            return getCatalogJsonFromDbWithRedisLock();//自旋的方式

        }
    }

    private Map<String, List<Catelog2Vo>> getDataFromDb() {
        String catalogJSON = redisTemplate.opsForValue().get("catalogJSON");
        if (!StringUtils.isEmpty(catalogJSON)){
            //缓存不为null直接返回
            Map<String, List<Catelog2Vo>> result = JSON.parseObject(catalogJSON,new TypeReference<Map<String, List<Catelog2Vo>>>(){});
            return result;
        }
        /**
         * 多次查询变成一次
         */
        List<CategoryEntity> selectList = baseMapper.selectList(null);

        //查出所有一级分类
        List<CategoryEntity> level1Categorys = getParent_cid(selectList,0L);

        //封装数据
        Map<String, List<Catelog2Vo>> parent_cid = level1Categorys.stream().collect(Collectors.toMap(k -> k.getCatId().toString(), v -> {
            //拿到每一个的一级分类,查到二级分类
            List<CategoryEntity> categoryEntities = getParent_cid(selectList,v.getCatId());
            List<Catelog2Vo> catelog2Vos = null;
            if (categoryEntities != null) {
                catelog2Vos = categoryEntities.stream().map(l2 -> {
                    Catelog2Vo catelog2Vo = new Catelog2Vo(v.getCatId().toString(), null, l2.getCatId().toString(), l2.getName());
                    //找当前二级分类的三级分类封装成vo
                    List<CategoryEntity> level3Catalog = getParent_cid(selectList,l2.getCatId());

                    if (level3Catalog!=null){
                        List<Catelog2Vo.Catelog3Vo> collect = level3Catalog.stream().map(l3 -> {
                            //封装指定格式
                            Catelog2Vo.Catelog3Vo catelog3Vo = new Catelog2Vo.Catelog3Vo( l2.getCatId().toString(), l3.getName() ,l3.getCatId().toString());
                            return catelog3Vo;
                        }).collect(Collectors.toList());
                        catelog2Vo.setCatalog3List(collect);

                    }

                    return catelog2Vo;
                }).collect(Collectors.toList());
            }
            return catelog2Vos;
        }));
        //查到的数据再放入缓存,将对象转为json字符串
        String s = JSON.toJSONString(parent_cid);
        redisTemplate.opsForValue().set("catalogJSON",s,1, TimeUnit.DAYS);
        return parent_cid;
    }

    //从数据库查询并封装
    public Map<String, List<Catelog2Vo>> getCatalogJsonFromDbWithLocalLock() {
        //只要是同一把锁，就能锁住这个锁的所有线程
        //TODO 本地锁：synchronized,JUC(lock)，在分布式情况下，想要锁住所有锁，必须使用分布式锁
        synchronized (this){
            //得到锁以后，我们应该再去缓存中确认一次，如果没有才继续查询
            return getDataFromDb();
        }
    }

    private List<CategoryEntity> getParent_cid(List<CategoryEntity> selectList,Long parent_cid) {
        List<CategoryEntity> collect = selectList.stream().filter(item -> item.getParentCid() == parent_cid).collect(Collectors.toList());
        //return baseMapper.selectList(new QueryWrapper<CategoryEntity>().eq("parent_cid", v.getCatId()));
        return collect;
    }

    private List<Long> findParentPath(Long catelogId,List<Long> paths){
        paths.add(catelogId);
        CategoryEntity byId = this.getById(catelogId);
        if(byId.getParentCid()!=0){
            findParentPath(byId.getParentCid(),paths);
        }
        return paths;
    }

    private List<CategoryEntity> getChildrens(CategoryEntity root,List<CategoryEntity> all){
        List<CategoryEntity> children = all.stream().filter(categoryEntity -> {
            return categoryEntity.getParentCid() == root.getCatId();
        }).map(categoryEntity -> {
            //找到子菜单
            categoryEntity.setChildren(getChildrens(categoryEntity,all));
            return categoryEntity;
        }).sorted((menu1,menu2)->{
            //排序
            return (menu1.getSort()==null?0:menu1.getSort()) - (menu2.getSort()==null?0:menu2.getSort());
        }).collect(Collectors.toList());

        return children;
    }
}